Developing device having developer bearing member and layer thickness regulating member

Abstract

In a developing device, a layer thickness regulating member, configured to regulate thickness of a layer of developer borne on a surface of a developer bearing member, includes: a first plate-shaped member having a pair of opposite ends in a perpendicular direction perpendicular to an axial direction of the developer bearing member, one end in the pair of opposite ends being in contact with the developer bearing member, the other end being supported by the casing; and a second plate-shaped member that is fixedly secured to the casing and that supports the first plate-shaped member. A seal member, which is in contact with an end portion of the developer bearing member in the axial direction of the developer bearing member, is in contact with an end portion of the first plate-shaped member in the axial direction of the developer bearing member. The second plate-shaped member holds the seal member.

What is claimed is: 
     
       1. A developing device comprising:
 a casing configured to accommodate developer therein; 
 a developer bearing member mounted in the casing so as to be rotatable about its axis and configured to bear developer thereon; 
 a layer thickness regulating member mounted in the casing and configured to regulate thickness of a layer of developer borne on a surface of the developer bearing member; and 
 a seal member that is in contact with an end portion of the developer bearing member in an axial direction of the developer bearing member, 
 the layer thickness regulating member including:
 a first plate-shaped member having a pair of opposite ends in a perpendicular direction that is perpendicular to the axial direction of the developer bearing member, one end in the pair of opposite ends being in contact with the developer bearing member, the other end being supported by the casing; and 
 a second plate-shaped member that is fixedly secured to the casing and that supports the first plate-shaped member, 
 
 the seal member being in contact with an end portion of the first plate-shaped member in the axial direction of the developer bearing member, and 
 the second plate-shaped member holding the seal member such that the seal member is located between the second plate-shaped member and the developer bearing member. 
 
     
     
       2. The developing device according to  claim 1 , wherein the second plate-shaped member includes:
 a first holding portion having a first holding surface that holds the seal member thereon; and 
 a second holding portion having a second holding surface that holds the first plate-shaped member thereon, 
 the first holding surface being positioned on an opposite side of the first plate-shaped member with respect to the second holding surface. 
 
     
     
       3. The developing device according to  claim 2 , wherein the first holding portion and the second holding portion are arranged to form a step. 
     
     
       4. The developing device according to  claim 3 , wherein the first holding portion and the second holding portion are integrally formed with each other from a metal plate, the step portion being formed by bending the metal plate. 
     
     
       5. The developing device according to  claim 3 , wherein the first holding portion and the second holding portion are formed from separate members, the step portion being formed by attaching the second holding portion onto the first holding surface. 
     
     
       6. The developing device according to  claim 5 , wherein either one of the first holding portion and the second holding portion is formed from resin, and the other one of the first holding portion and the second holding portion is formed from metal. 
     
     
       7. The developing device according to  claim 1 , wherein an end face of the first plate-shaped member in the axial direction of the developer bearing member is in abutment contact with an inner-side end face of the seal member in the axial direction of the developer bearing member. 
     
     
       8. The developing device according to  claim 1 , wherein an inner-side end portion of the seal member in the axial direction of the developer bearing member is sandwiched between the second plate-shaped member and the end portion of the first plate-shaped member in the axial direction of the developer bearing member. 
     
     
       9. The developing device according to  claim 1 , wherein the one end has a contact portion being in contact with the developing bearing member, and
 wherein the first plate-shaped member is positioned such that a rotation direction of the developer bearing member at the contact portion is substantially the same as a direction directed from the other end to the one end of the first plate-shaped member in the perpendicular direction. 
 
     
     
       10. A developing device comprising:
 a casing configured to accommodate developer therein; 
 a developer bearing member mounted in the casing so as to be rotatable about its axis and configured to bear developer thereon; 
 a layer thickness regulating member mounted in the casing and configured to regulate thickness of a layer of developer borne on a surface of the developer bearing member; and 
 a seal member that is in contact with an end portion of the developer bearing member in an axial direction of the developer bearing member, 
 the layer thickness regulating member including:
 a first plate-shaped member having a pair of opposite ends in a perpendicular direction that is perpendicular to the axial direction of the developer bearing member, one end in the pair of opposite ends being in contact with the developer bearing member, the other end being supported by the casing; and 
 a second plate-shaped member that is fixedly secured to the casing and that supports the first plate-shaped member, 
 
 the seal member being in contact with an end portion of the first plate-shaped member in the axial direction of the developer bearing member, and 
 the second plate-shaped member holding the seal member, wherein the second plate-shaped member includes:
 a first holding portion having a first holding surface that holds the seal member thereon; and 
 a second holding portion having a second holding surface that holds the first plate-shaped member thereon, 
 the first holding surface being positioned on an opposite side of the first plate-shaped member with respect to the second holding surface. 
 
 
     
     
       11. The developing device according to  claim 10 , wherein the first holding portion and the second holding portion are arranged to form a step. 
     
     
       12. The developing device according to  claim 11 , wherein the first holding portion and the second holding portion are integrally formed with each other from a metal plate, the step portion being formed by bending the metal plate. 
     
     
       13. The developing device according to  claim 11 , wherein the first holding portion and the second holding portion are formed from separate members, the step portion being formed by attaching the second holding portion onto the first holding surface. 
     
     
       14. The developing device according to  claim 13 , wherein either one of the first holding portion and the second holding portion is formed from resin, and the other one of the first holding portion and the second holding portion is formed from metal. 
     
     
       15. The developing device according to  claim 10 , wherein an end face of the first plate-shaped member in the axial direction of the developer bearing member is in abutment contact with an inner-side end face of the seal member in the axial direction of the developer bearing member. 
     
     
       16. The developing device according to  claim 10 , wherein an inner-side end portion of the seal member in the axial direction of the developer bearing member is sandwiched between the second plate-shaped member and the end portion of the first plate-shaped member in the axial direction of the developer bearing member. 
     
     
       17. The developing device according to  claim 10 , wherein the one end has a contact portion being in contact with the developing bearing member, and
 wherein the first plate-shaped member is positioned such that a rotation direction of the developer bearing member at the contact portion is substantially the same as a direction directed from the other end to the one end of the first plate-shaped member in the perpendicular direction.